Method and means for making diamond drill bits



' Nov.A 24, 1942.y L HAyLlcK 2,303,046

ETHOD AND MEANS FOR MAKING DIAMONDDRILVL BITS Filed' lay '1, .1942a'sheets-sneer 1 riff v Inventorl ttorney Nav. 24, 1942.. 'J.'|. HAVLICK2,303,045 METHOD AND MEANS .VFORVMAKING DIAMOND DRILL r'rs Fiied may 1.1942 :s sheets-Sheep 2 Nv 24. 1942. J. 1. HAvLlcx 2 ,3035046 METHOD ANDMEANS FOR MAKING DIAMOND DRILL IaII's Fn'ed lay 1,l 1942 s 'sheets-sheervs' Inventor dfssf L' HAM )6K like parts throughout,

' Patented Nov. 24, 1942 METHOD AND MEANS FOB MAKING DIAMOND DRILL BITS:me L. annex, spouse, wash. Applicashun 1, mz, serai N0. 441.401

(ci. zz`1zz 7Claims.

'I'he presentl invention relates to new and useful improvements inmethod and means for making rotary diamond drill bits for earth boring.and for making other diamond cutters and tools.

H eretofore the practice oi setting diamonds as cutters in industrialtools has been a slow and tedious method done principally by hand andthis, of course, is expensive as it is necessary to drill the hole theproper size and depth for the diamond, setting the diamond inthe hole.by

hand, andv then drawing the metal around the stone by means of calkingwhich makes it impossible for the hand-setter to apply exactly the sameamount .of pressure to the stone on all sides, which is very importantin avoiding putting extensive stresses on the stone which may causefractures or breaksbefore the stone is ever used.

Also a method of setting the diamonds has been employed by casting thesame in slugs, or molten metal, but because of the difference inspecific gravityof the diamond, it is very dimcult to noia the diamondinposition while casting. This method has also presented diiilculties ineliminating so-called iloatingf which occurs when the diamond has raised'in' the molten metal before it has properly set.

Accordingly, it is an object of the present invention to overcomethe'dimculties above explained and to this end I have provided a methodand apparatus for setting the diamonds by providing a temporary mold.and inverting the mold with the diamond held in position therein ontopowdered metal placed in a mold on top of the bit blank and fusing themetal and subjecting the -same to predetermined pressure `toy produce astrong connection thereof with the bit blank and in which the 'diamondwill be rmly embedded.

A further object is to provide 'a method and means ofsetting Adiamondsindrill bits andthe like which are emcient and reliable in performance,relatively inexpensive to use and other-- wise well adapted for the sameis intended.

Other objects and advantages reside in the details of construction andoperation as more fully hereinafter described and claimed, .referencebeing had to the accompanying drawings forming part hereof, wherein likenumerals refer to and in which: plan view of the mold on purposes forwhich the Figure 1 is a top diamond holder.

Figure 2 is a side elevational view thereof.

Figure 3 is a sectional view taken substantially oxialincS-lofFigureFigure 4 is a vertical sectional view of the suction device for-holdingthe diamonds in position -in the mold or holder 4 v /hile the diamondsare temporarily secured in position in the mold.

Figure 5 is a side elevational view of a comr pleted diamond bitconstructed in accordance with my invention.

Figure 6 is a vertical sectional view thereof. Figure 'l is anendelevational view. A Figure 8 is a vertical sectional view of the fusingmold. f

Figure 9 is a sectional view taken substantially on a line 9-9 of Figure8.

Figure l0is a front elevational view of the combinationelectro-hydraulic pressure fusing or sintering machine.

Figure 11 is a side elevational view thereof, and Figure 12 is asectional view taken substantially on a linen-I2 of Figure l0. 1

Referring now to the drawings `in detail, thenumeral l designates adiamond-holding mold or cup-having an annular channel l formed therein lwithin whichthe diamonds, indicated at 'l in Figure 4'of the drawings,are placed in a desired position. the bottom oi' the channel I havingopenings l therein to 'subject the diamonds to suction from a suctionchamber I in which the l mold l may be positionedv and supported in itsupper portion on brackets IO, the center portion of the chamber I beingclosed by a cap il. A 'suction pipe I! is attached to the chamber 9 for`:resting the desired suction in the chamber from a suitable source ofpower.

The diamonds are then sprayed with a suitable quick-drying adhesive suchas collodion, shellac,

lacquer or glue, this being a temporary operation Y to hold the diamondsin the mold while handling; The mold, with the diamonds positionedtherein, is then 'placed in an inverted position in a combined fusingand pressure device illustrated in detail in Figures 8 and 9 of thedrawings. and

comprises a bottom section I3 of conductive l. material including anupstanding tubular post Il which is internally threaded for threadedlyreceiving the bit blank il, the bit blank having lateral openings Itadjacent its upper edge. g

Positioned inthe upper portion of the bit blank is a' core II ofnon-conductive material which may be made of bone aah, plaster ofParis.. or

refractory brick material, and surrounding the upper portion of the bitblank andthe upper portion of the tubular bit-blank sectional liningsleeve Il of material similar to the core i1. A retaining collar Il isthen placed over the lining Il.

holder I4, is a depending upon molten metal to enter the aperturevBetween the core I1 and the lining I8 is placed a quantity of powderedmetal 20 screened to about 200 mesh, the powdered metal being placed ontop of the bit blank I5 and on top of the powdered metal is inverted thediamond holding mold 5.

The powdered metal may be a suitable alloy, the type of material thefinished bit is to be used for boring.

On top of the mold 5 is placed the upper section 2l fof the fusingdevice which has its .lower end extending downwardly into the sectionallining I8 for bearing against the mold 5, the

cause embedding of the diamonds therein and adherence of the material toth`e stock.

3. A method of making diamond cutters comprising placing the diamonds inan open holder ence of the material to section 2l likewise being ofconductive material. i

Connected to the section ber 22 and connected to the lower section I3 isa terminal member 2,3, said terminals leading to a suitable source ofdirect current.

The fusing device is then placed in a hydraulic press designatedgenerally at 24 and includes 2I is a terminal mem-- a base 25 havinga'pair of upstanding rods 26 rising therefrom on which isslidablymounted the lower pressure plate 21 on which the -Ifusing deviceI3 is supported, the upper ends of -the rods 26 having an upper pressureplate 28 attached thereto and whichengages the top of the section 2| ofthe fusing device I3. The hydraulic cylinder 29 is supported on the base25 and from the top of the cylinder projects the plungeril for engagingthe underside ofthe lowerpressure plate 21. A feed pipe 3| leads fromthe cylinder 29 to a suitable source of hydraulicv pressure whereby thedesired pressure may be subjected to the metal powder 20 and at the sametime a .heavyV electric current of high amperage and density istransmitted to the upper and .lower sections of the bit holder throughthe terminals 22 and 23 which then fuses the powdered metal and causesthe diamonds to become embedded therein. The fusing action also causesthe I6 to firmly anchor the csaine to the bit.

After the bit holder and bit have been cooled, the diamond holder 5 isthen removed and the bit is ready for use.

Having thus described claim is:

1. A method of making diamond cutters comprising temporarilysecuring thediamonds in an open mold, inverting the mold on metal, and

the invention A what I monds therein.

2. A method of makingdiamond cutters corn.-Y prising placing thediamonds in an open holder mined number of diamonds against vfusing themetal to cause embedding .of the dia-*jV and coating the'diamonds withan adhesive to s55 temporarily secure the diamonds, in position in theholder, inverting the holder on a cutter stock, interposing fusible.material between the, diamonds and the stock, and fusing the materialto and coating the diamonds with an adhesive to temporarily secure thediamonds in position in the holder, inverting the holder on a cutterstock, interposing fusible material between the diamonds and the stock,subjecting the diamonds and the stock to va compressing action againstthe material, and fusing the material to cause embedding of the diamondstherein and adherthe stock. r

4. A method of making diamond cutters comprising placing the diamonds inan open holder and coating the diamonds with an adhesive to temporarilysecure the diamonds in position in the holder, inverting the holder on acutter stock, placing powdered metal between the diamonds and thestock,'and fusing the metal to the diamonds and the stock.

5. A method of making diamond cutters comprising placing the diamonds inan open holder and coating the diamonds with an adhesive to temporarilysecure the diamonds in position in the holder, inverting the holder on acutter stock, placing powdered` metal between the diamonds and thestock, compressing the metal between the diamonds and the stock, andfusing the metal to the diamonds and the stock. 6. vMeans for makingcutting tools comprising an open holder adapted to contain apredetermovement in the holder in an exposed position, a fusing moldcomprising upper and lower electric conductors, said lower conductorbeing adapted for supporting a tool stock, and for receiving powderedmetal placed in the mold on the upper edge of the stock to be fused tothe stock, said holder being positioned on top of the metal in aninverted position withthe diamonds in contact with the metal, and meansfor compressing the diamonds and stock against the metal.

'1. Means for making cutting tools comprising an open holder adapted tocontain a predetermined number of diamonds against movement in theholder in an exposed position, .a fusing mold comprising upper and lowerelectric conductors, said lower conductor being adapted for supporting atool stock,- and for receiving powdered metal placed in the mold on theupper edge of the stock to be fused to the stock, said holder beingpositioned on top of the metal in an inverted position with the diamondsiny contact with the metal, and means for exerting pressure against theconductors for compressing the metal between the diamonds and stock.

JESSE L. HAVLICK.

